Apparatus for distilling dry cleaners&#39; solvent



Nov. 14, 1933. C, H. HAPGOOD y 1,935,183

APPARATUS FOR DISTILLING DRY CLEANERS SOLVENT Filed Jan. 3, 1929 2Sheets-Sheet l Nov. 14, 1933. c. H. HAPGooD 1,935,183

APPARA'IUSA FOR DISTILLING DRY CLEANERS SOLVENT Filed Jan. 3, 1929 2Sheets-Sheet 2 Cnus/warn/: 000 wifi@ 7 @gy f CIA 1n which- Patented Nov.14, 1933v -llNirso .STATES ,flessdss earner vorgie-r;

APPARATUS DISTILLING DRY CLEANERS SOLVENT f Cyrus Howard Hapgood,Nutley, N. assigner to vThe De Laval `Separator Company, New York, N.Y., a corporation of New Jersey ApplicationrJanuaryB, 1929. Serial No.330,009

16 claims.' (01; 19e- 15) l The object of my invention is to provide astillfor the distillation of dry cleaners solvent, gaso- My inventioncomprises a still responding to.

the above requirements and having also other advantages, particularlyeconomyin consumption of heat, continuity of operation, prevention ofaccumulation of vpermanent gases, andavoidance of loss of solvent vaporwith permanent gases.

A still embodying my invention in a preferred form isshown in theaccompanyingdrawings,

Y Fig'. lis a general elevation of the apparatus, vpartly inA section. o

Figs. 2 and 3A are,`respectively, a sectional plan View and elevationofthe evaporator.

The machine comprises a solvent cooling chamber c, a solventevaporatingchamber b nl'ountedV v on the'cooling chamber, a heatexchanging 'cham'- ber a mounted on the evaporating chamber, and coilsand pipe connections as hereinafter described.

The solvent a pipe d into and through a coil of pipe e in the chambera,wherein the solvent isv preliminarily, heated by 'heat ,exchange withsolvent vapors as hereinafter described. The heated liquid solventthence 'flows through a pipe f,` in which is interposed a feedlregulator g, into the evaporating chamber b. In chamber. b are a coilor coils of pipe h' through which circulates'steam, which evaporates thesolvent, leaving a residue containing impurities and which, `from timeto time, may be withdrawn through drain i. l

The .solvent vapor rises and enters chamber a, wherein it transfers muchof its heat to the inflowingsolvent in coil e, the vaporbeing largelycondensed and flowingdown, through a piped', into the cooling chamber c.'y

Extending through pipe y is a tubelc (preferably composed of 'asbestoscovered with sheetmetal), the upper part of which is expanded to form a.funnel-shaped upper end m extending outside the coil e near the Wall ofchamber a, leaving an annular space between it and the wall for the'yupiiow v1of vsolvent vapor. If the Vfunnel were liquid to be distilledcows through j l 'solvent vapor that may be entrained therewith,

eliminated, the vapor wouldfnot be compelled to flow into heat exchangerelation with an effective length of the coile and there would'be Y.Very partial condensation with limited heat transfer.V The'funnelalsoacts to collect solvent that 60 has condensed and deliver it to tubek. The

Vtube it andfunnel m are made of non-heat conducting material in orderthat the solvent should not be reheated inthe course of its downiiowthrough funnel m and tubec,

In chamber c are a c'oilv or coils o fv pipe n through which circulatescold `water,whe'reby the remaining vapor flowing from heat exchanger a,is condensed and the condensate is cooled. The lcooled solvent ispumped out through pipe o and thence through pipe p; the pump, notshown, being positioned on pipe p or an extension thereof.

' rt is preferred to make coils h inthe solvent evaporating' chamber,asshown in Figs. 2 and 3, namely, of tubing which is relatively Wide andthin in cross-section and which is wound'upon itself spirally; therebeins7 preferably a number of coils arranged in multiple and'connected,at top andfbottom, withmanifolds randy; The coils n in the solventcooling chamber may be of any conventional type. Y In the evaporatingoperation, 'a small amount of permanent gas maybe 'driven off which,without some provision rto prevent it, would accumulate in the top' ofchamber a and ultimately pre- 85 vent the successful operation of thestill. lSuch permanent gas, together with small amounts rof kcarriedaway, through pipe ip, with the cooled solvent from pipe o K Itis founddesirable to maintain as higha vacuum as possible in the chambers a, band vc when distilling. v l

j The pipe l1*connected with pipe 1` and regulator g functions tovequalize thepressure between the solvent evaporating chamber b andthefeed regulator g.f If lthis pressure were not equalized, the

liquid levels in solvent evaporating chamber lb,

andthe feed regulator g would not be maintained the same.V

Among the fnovelstructural features and lad- 1710 vantages may beenumerated the following:

The heat exchanger is, in eiiect, the upper part of the evaporatorchamber.

Means are provided for accumulating the condensed vapors which arecondensed by the heat exchanging coils and for conveying said condensedvapors, by gravity, with the uncondensed vapors, to the condenser.

The top of the heat exchange chamber is connected by a pipe with thebottom of the condenser chamber to equalize pressure, the pipe having aloop below the liquid level of the condenser to form a liquid seal.

The suction line to the pump is taken oli of this pressure equalizingline at the level of the condensed liquid in the condenser.

rThe pump has greater capacity than actually needed to remove liquidfrom the condenser, the excess capacity of the pump being utilized fordrawing non-condensible vapors from the top of the heat exchange chamberdown through the equalizer pipe and with the condensed liquid throughthe pump. 1n this way one pump serves as both a wet vacuum pump'toremove only liquid from the bottom of condenser c and as a l'dry vacuumpump to remove only gases from the exchanger.

' The lower part of the equalizer pipe is watercooled in order tocondense such condensible gases as may be drawn Vdown through thisequalizer pipe from the top of the heat exchange chamber.

- Having now fully described my invention, what I claim and desire toprotect by Letters Patent 1s:

l. Ay still for, distilling liquid such as dry cleaners solvent, whichcomprises a solvent coolving chamber, a solvent evaporating chamber, a

heat exchange chamber in the upper part of the evaporating chamber, acoil in the heat exchange chamber through which the solvent to bedistilled flows and in which the solvent is prelimjinarily lheated bysolvent vapor and the discharge end of which extends downward and opensinto the evaporating'chamber, means affording communication between theevaporating chamber and the heat exchange` chamber for the upward flowof solvent vapor, means affording a closed passage for the flow ofsolvent from the heat exchangeA chamber downward through the'evaporating chamberto the cooling chamber, a coil in the cooling chamberthrough which a cooling fluid is adapted to flow to effect cooling ofthe solvent, and means for outiiow of cooled solvent from the coolingchamber.

2. A still for distilling liquid such as dry cleaners solvent, whichcomprises a lower cooling chamber in which solvent is condensed andcooled, a middle evaporating chamber, above the cooling chamber, inwhichsolvent is evaporated, an upper chamber above the evaporating chambervinwhich solventis preheated by heat exchange with solvent vapor, means toconvey solvent through the upper chamber to the middle chamber, meansfor passage of solvent vapor from the middle chamber to the upperchamber, means providing a passage for solvent from the upper chamber,through, but out of heat-conducting relation with, the middle chamber,to

the lower chamber, and means to withdraw cooled'solvent from the lowerchamber.

3. A still for distilling liquids such as dry cleaners solvent, whichcomprises 'a solvent cooling chamber, meanstherein to cool the solvent,a second chamber, means to effect evaporation of the solvent in thelower part of the second chamber, means in the upper part of the secondchamber to effect heat exchange between the solvent vapors and theinflowing solvent before the latter is evaporated, and a conduit foroutiiow of cooled and condensed vapors from the upper part of the secondchamber to the cooling chamber and providing a space between it and thewall of the second chamber for inflow of vapors from the locus ofevaporation tothe locus of heat exchange.

4. A still for distilling liquid such as dry cleaners solvent, whichcomprises a lower cooling chamber in which solvent is condensed andcooled, a middle evaporating chamber, above the cooling chamber, inwhich solvent is evaporated, an upper chamber above the evaporatingchamber in which solvent is preheated by heat exchange with solventvapor, means to convey solvent through the upper chamber to the middlechamber, a pipe connecting the upper and lower chambers and extendingthrough the middle chamber, and means providing an annular passage forvapor from'the middle chamber along the lower Wall of the upper chamber,said passage cpening into the upper chamber a substantial distance belowthe upper end thereof.

v5. A' still for distilling liquids such as dry cleaners solvent, whichcomprises a solvent cooling chamber, means therein to cool the solvent,a second chamber, means to effect evaporation of the solvent in thelower part of the second chamber, means in the upper part ofthe secondchamber to effect heat exchange between the solventvapors and theiniiowing solvent before vthe latter is evaporated, a pipe providing apassage for downiiow of condensed solvent and uncondensed vapors, saidpipe extending rthrough the lower part of said second chamber andexpandedk 6. A still for distilling liquid -such as dry cleanerssolvent, which comprises a solvent cool- Y ing chamber, a second chambersuperimposed of the solvent cooling chamber, a heat exchanger in theupper part of the second chamber through which solvent to be distilledflows and in which the solvent is adapted to be preliminarily heated bysolvent vapors, an evaporator in the lower part of said second chamber,a conduit for the Vpassage of solvent from the heat exchanger downwardto the evaporator, and a conduit affording within it a passage forcondensate from the heat exchanger downward to the cooling chamber andaround the outside of which solvent vapors are adapted to flow upwardfrom the evaporator to the heat exchanger. v

'7. A` still for distilling liquid such as dry cleaners solvent, whichcomprises a lower cooling chamber in which condensed solvent is cooled,a .middle evaporating chamber, above the cooling chamber, in whichsolvent is evaporated, an upper chamber above the evaporating chamber inwhich solvent is preheated byA heat `lower chambers and expanded at itsupper end t'o A.provide `a narrow annular passage between its upper endand the inner wall of the upper charnits ber, the upper end of said'passage terminating;

substantially above thebottom andsubstantially belowthe'top ofthe upperchamber, the solvent vapor flowingthroughsaid passage from the lmiddlechamber "into the vupper chamber.

8. A still for distillingliquid -such as dry'cleanerssolvent, whichcomprises Aa chamberthrough which are adapted to'flow` solvent-to beevaporated and, in vheat exchange-relation-therewith,

solvent vapor, an evapora'ting"v chamberv adapted to receivepreheatedsolvent from the rst cham# ber and v from which `solvent vapor isadapted to flow into the first chamber, a cooling chamber adapted toreceive solvent from rthe'rst charnber, means in the respective chambersto effect said heat exchange, evaporation and cooling, a

pipe communicating with the upper part of the vapors from theevaporating chamber are largely condensed by heat exchange with solventflowing toward the evaporating chamber, means in the respective chambersto effect said cooling, evapo-v ration and heat exchange, means toconvey so1' vent from the heat exchanging chamber to the coolingchamber, 'and a pressure equalizing pipe line between the vapor spacenthe top' of the heat exchanging chamberrand the bottom discharge fromthe cooling chamber. 'Y

10. A still for distilling liquids such as dry cleaners solvent,whichcomprises a solventcool-v ing chamber, a solvent evaporating chamber, ,aheat exchange chamber in which the vapors from the evaporating chamberare largely condensed by heat exchange withV solvent flowing toward theevaporating chamber, means in the respective chambersto effect saidcooling, evaporation and heat exchange, means to convey solvent from theheat exchanging chamber to Athe cooling chamber, and a pressureequalizing'pipe line between the top of the heat exchanging chamber andthe bottom of the cooling chamber, said pipe line havingra loop belowthe liquid level of the cooling chamber to form a liquid seal. a

11. A still for distilling/liquids such as dry cleaners solvent, whichcomprises a solvent cooling chamber, a solvent evaporating chamber, laheat exchange chamber in which the vapors from e the evaporating chamberare largely condensed by heat exchange with solvent owing toward theevaporating chamber, means in the respective chambers to effect saidcooling, evaporation and heat exchange chamber, and a lthird pipeconnected with the other two pipes and through which both cooled solventand incondensible gas may be withdrawn from the still. I

12. A still for distilling liquid such as dry c1eaners solvent, whichcomprises la chamber through which are adapted to flow solvent to be 1evapqatedandgfin heat* exchange relationtneref with; solvent"v'apor,-'an evaporating chamber adapted to receive preheatedsolvent from the vfirst c h'arr'iber i and *from which solvent vapor is adapted Ito flowinto 'the `i'irst chamber, "a cooling chamberv adapted'to receivesolventfrom the viirst chambe'nVmeans inthe respective chambers-'to Veffectsaid heat exchange; evaporation and cooling, 1 a pipe communicating withfthe upper 1 `part of the vfirstchamber and adapted to receivevaportherefrom,"and means adapted tofconvey accolingffluid into' heatexchangefrelation vwith said vapor pipe and thence through the coolingchamber into heat exchange relation with the solvent y Y therein.

13. A still for distilling liquid such as dry cleaners solvent whichcomprises a solvent cool-r` ing` chamber, an evaporator, a heatexchanger adapted to receive solvent vapors from the' evapo-` ratorandin which the solvent to be distilled is l incondensible vapors fromthe heat exchanger and condensed solvent from the cooling chamber, saidmeans being so arranged as to provide a liquid seal formed-,by condensedsolvent between said cooling chamber and said pipe.`

' 14. A still Vfor'distilling liquids such as dry cleanerssolvent,vwhich comprises a solvent cooll ing chamber, a solventevaporating chamber, a

, heat exchange chamber in which thefvapors from the evaporating chamberarelargely condensed by heat exchange with solvent flowing toward the``evaporating chamber,` means, in the respective 'chambers to effect saidcooling, evaporation and heat exchange, means to convey solvent from theheat exchange chamber to the cooling chamber,

1a pressure equalizing pipe line between the top of the heat exchangingchamber and the bot-'- tom of the cooling chamber, and a` pipe connectedA'with said pipe line Vand through which cooled vsolvent from thecoolingy chamber and mooncleaners solvent, which comprises a solventcool' ing chamber, a solvent evaporating chamber, va

heat exchange chamber in which the vapors from the evaporating chamberare largely condensed by heat exchange with solvent owing toward theevaporating chamber, means in the respective vchambers to effect saidcooling, evaporation and heat exchange, means to convey solvent from theheat exchange chamber to the coolingcham# ber, a pipe through which thecooled solvent is'adapted to outflow from the cooling chamber, a secondpipe communicating with Vthe upper part of the heat exchange chamber andthrough which incondensible gas'is adapted to outiiow from the heatexchange chamber, a third pipe connected with the other two pipes andthrough which both cooled solvent and incondensible gas may bewithdrawnfrom the still, and means to cool theincondensible gas flowingthrough the first pipe wherebyV any solvent vapors entrained therewithwill be condensed and withdrawn through the third pipe.

16. A still for distilling liquids such as dry the-heat exchange chamberto the cooling chamber, a pipe through Which the cooled solvent isadapted to outflow from the cooling chamber, a'second pipe through whichincondensible gas is adapted to outow from the heat exchange cham-rber,V av third pipe connected With'the other'tvvo pipes and throughwhich both cooled solvent andincondensible gas may be Withdrawn from thestill, and means to coolthe inconden'siblegas.

flowingvthrough the secondpipewhereby anyV solvent vapors entrainedtherewith willbe condensed, said cooling means comprising al jacketsurrounding lsuch ,pipe and throughk which the. cooling medium for thesolvent is adapted to, flovv' 'on'its Way to the cooling chamber.

CYRUS HOWARD HAPGoz'DD:v

